body {
    background-color: #F7F8F9;
}
* {
    margin: 0;
    padding: 0;
}
.clear::after {
    content: '';         
    display: block;    
    clear: both;         
}
.z1 {
    display: flex;
    margin: 0 auto;
    width: 1500px;
} 
.b1 {
    width: 100%;
    background-color: #fff;
    box-shadow: 0px 0px 5px #aaa ;
    position: fixed; 
    top: 0px;

}
.b1 li {
    list-style: none;
    line-height: 50px;
}
.b1 a {
    text-decoration: none;
    color: #AAAAAA;
    font-size: 14px;
}
.b1 ul {
    margin-left: 50px;
    display: flex;
    justify-content:space-around ;
    width: 1500px;
    margin: 0 auto;
}

.b1 input {
    height: 22px;
    border: 1px solid #AAAAAA;
    color: #aaa;
    outline: none;
    padding: 0 5px;
    border-radius: 20px;
    background-color: #fff;
    margin-top: 15px;
}
/* 中间左半部分 */
.b2 {
    background-color: #fff;
    /* border: 1px solid red; */
    width: 900px;
    margin: 100px 0 0 200px;
    box-shadow: 0px 0px 5px #aaa ;
    height: 1800px;
    padding: ;
}
/* 第一行 */
.b2 .c1 {
    display: flex;
    justify-content: space-around;
    margin: 10px 0;
}
.b2 .d1 {
    width: 400px;
    display: flex;
    justify-content: space-between;
    border-bottom: 1px solid #aaa;
    padding: 20px 0;
}
.b2 .d2 {
    width: 400px;
    display: flex;
    justify-content: space-between;
    border-bottom: 1px solid #aaa;
    padding: 20px 0;
}
.b2 .c1 h3 {
    font-weight: 400;
    font-size: 16px;
}
.b2 .c1 div.e1 {
    font-size: 14px;
    color: #aaa;
}
/* 第二行 */
.b2 .c2 {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
}
.b2 .c2 .d3 {
    width: 400px;
}
.b2 .c2 .d4 {
    width: 400px;
    height: 300px;
}
.b2 .c2 .d3 h3 {
font-weight: 400;
margin: 5px 0;
font-size: 14px;
}
.b2 .c2 .d3 p {
    color: #aaa;
    font-size: 12px;
    margin-bottom: 10px;
}
.b2 .c2 ul {
padding:0 20px;
}
.b2 .c2 ul li {
   font-size: 12px;
}

.b2 .c2 .d4 h3 {
    font-weight: 400;
    margin: 5px 0;
    font-size: 14px;
    }
    .b2 .c2 .d4 p {
        color: #aaa;
        font-size: 12px;
        margin-bottom: 10px;
    }
    /* 第三行 */
   .b2 .c2 .d5 img {
       margin:0 20px;
       width: 850px;
   }
    
    /* 中间右半部分 */
    .b3 {
        width: 400px;
        /* float: right; */
        /* height: 300px;  */
        /* background-color: gold;  */
       margin: 100px 50px 0 30px;
    }
    .b3>div {
        height: 300px;
        margin-bottom: 30px;
        background-color: #fff;
        box-shadow: 0px 0px 5px #aaa ;
    }
    /* 底部 */
    .b4 {
        height: 500px;
        background-color: #fff;
        margin-top:50px;
        box-shadow: 0px 0px 5px #aaa ;
    }